GeoTechnology

The flashcards below were created by user kamrunsreno on FreezingBlue Flashcards.

1. Major Components of a Map
• Scale bar
• legend
• North Arrow
• Title
• Discription
• Source
• Locator Map
• Border
• Credit
2. Map Geometry
Symbols occupy more space than they generally take up based on the scale

Linear widths, sometimes rivers are lines on a map other times they are polygons (question of scale and what is the real width of the river)

3. Elementary Geometric Operations (Linear Features)
4. Elementary Geometric Operations
(Point Features)
5. Elementary Geometrick Operations
(Area Features)
6. Map Symbology (NPS)
7. Symbol (USGS)
8. Meridian
A plane that passes through the center of the Earth

For reference in projection terms a meridian passes through the poles

Since all are equal a prime meridian had to be selected

Longitude lines of the Earth’s graticule
9. Parallel
Lines placed at right angles to the meridians

The equator is a parallel and is the main reference point for projections

Latitude lines of the Earth’s graticule
10. Coordinate System
Global systems

– Most commonly used latitude and longitude

• • Reno, NV
• – Latitude 39° 30’ 30” North
• – Longitude -119° 48’ 30” West

• Degrees, Minutes, Seconds (dms)

• • Decimal Degrees (dd)
• – Latitude 39.508333333
• – Longitude -119.80833333

• • Conversion to decimal degrees
• – decimal deg. = degrees + (minutes / 60) + (seconds / 3600)
11. Spheroid
A three-dimensional shape obtained by rotating an ellipse about its minor axis, with dimensions that either approximate the earth as a whole, or with a part that approximates the corresponding portion of the geoid.

The shape and size of a coordinate system is defined by the spheroid

Smaller scale systems can assume sphere shape for earth (more on that later)

Most created with a specific region in mind
12. Geoid
Earth not a true ellipse or sphere, but has an irregular shape. This shape is called a geoid.

Think in terms of the highest mountain peak and the lowest ocean valley
13. Conical Map Projections
• Albers equal-area
• Conical can also be good for distances
• Scale and shape distorted
14. Cylindrical
• Distortion different close to poles
• Meridians are now the important points
• UTM zones run north-south with a central meridian
15. Azimuthal
• Projections onto a plane
• Good for direction
• Map distances can be computed by a function
 Author: kamrunsreno ID: 173140 Card Set: GeoTechnology Updated: 2012-09-25 01:42:18 Tags: Geo Technology Folders: Description: Exam 1 Show Answers: